DE102019109658A1 - GENERAL STRATEGY FOR REDUCING COLD START EMISSIONS - Google Patents

Abstract

One system that provides a catalyst warm-up mode approach is applicable to a number of vehicle applications, including hybrid vehicles. The system determines the exhaust enthalpy under conditions such as transient engine speed and transient engine load for a catalyst that receives the exhaust power of an engine. Several exhaust gas parameter measuring devices each measure the exhaust gas conditions entering the catalyst. A processor receives the output from each of the exhaust gas parameter measuring devices and continuously calculates an enthalpy of the catalyst. The calculated enthalpy of the catalyst is repeatedly compared to a predetermined enthalpy threshold required to achieve a catalyst shutdown stored in a memory.

Description

INTRODUCTION

The present disclosure relates to the reduction of the cold start emission of automotive engines and the catalyst operation.

The strategy for reducing the cold start emissions of vehicles is normally implemented at stable engine speeds and load conditions. Normally, a predetermined time is provided for catalyst heating of a catalyst prior to the implementation of emission strategies. Increased idling of the engine using one or both of the ignition retarders together with the increase in engine speed is normally performed for a predetermined period of time, for example, about 10 to 20 seconds, whereupon it is assumed that the catalyst shutdown has taken place and oxidation and reduction processes of the catalyst take place ,

Newer powertrain technologies may require the implementation of emission reduction regardless of engine condition, which may require catalyst warm-up during transient engine speed and load. Under these conditions, the predetermined period for the engine's increased idle time is not available or is not reached, and therefore the set target for both the spark retarded and accumulated engine speeds is not achieved. Therefore, a new approach to reducing cold start emissions under transient engine speed and load conditions is required.

Although current strategies to reduce vehicle cold-start emissions are fulfilling their purpose, a new and improved system and methodology for implementing the cold-start strategy for emissions is needed.

SUMMARY

In various aspects, a system for determining catalytic cut-off conditions during transient engine speed and transient engine load includes a catalyst that receives exhaust emissions from an engine. At least one exhaust gas parameter measuring device measures at least one parameter of the exhaust gas entering the catalytic converter. A processor accepts the delivery of the at least one exhaust gas parameter measuring device and continuously calculates an enthalpy of the catalyst. The calculated enthalpy of the catalyst is repeatedly compared to a predetermined enthalpy threshold required to achieve a catalyst shutdown stored in a memory.

In another aspect of the present disclosure, inputs from a calculation block, including an exhaust gas inlet temperature, a mass air flow, a mass fuel flow, and a catalyst warm-up mode state, are received to calculate the enthalpy of the catalyst.

In another aspect of the present disclosure, in the calculation block, the state of the catalyst warm-up mode, which is true, is determined prior to starting the calculation of the enthalpy of the catalyst, the state of the catalyst warm-up mode being true, identifies whether the catalyst is at a temperature below that temperature required for the catalytic dimming.

In another aspect of the present disclosure, a cumulative mass flow is calculated on the catalyst passed by the processor; and in a comparison block, a determination is made if a) the calculated enthalpy of the catalyst is greater than the predetermined enthalpy threshold, and b) if the cumulative mass flow is less than a predetermined cumulative mass flow threshold.

In another aspect of the present disclosure, when an output from the comparison block for (a) and (b) is positive, a diagnostic through signal is generated.

In another aspect of the present disclosure, when an output from the comparison block for (a) and (b) is negative, a diagnostic error signal is generated.

In another aspect of the present disclosure, a cumulative mass flow is calculated on the catalyst passed by the processor; and in a determination block, it is determined that the state of the warm-up mode of the catalyst is false, and whether the cumulative mass flow is greater than a predetermined minimum threshold.

In another aspect of the present disclosure, when the determination block is positive, an undetermined diagnostic test signal is generated.

In another aspect of the present disclosure, in a determination block, an activated status of a catalyst warm-up mode is determined, and if an output from the determination block indicating that the catalyst warm-up mode is activated is positive, a request for a torque reserve for increasing an exhaust temperature is made; and the Torque reserve is calculated and integrated after the request for the torque reserve in a first calculation block.

In another aspect of the present disclosure, a result from the calculation block is input as a first variable into a comparison block; and a second calculation block provides a second variable defining an energy threshold required to achieve catalyst radiation to the comparison block.

In another aspect of the present disclosure, the energy threshold required to achieve a catalyst shutdown defining the second variable is integrated as a cumulative value of the exhaust stream; and in the comparison block, the second variable is compared with the first variable to determine if the second variable is greater than the first variable, and if an output from the comparison block is negative, the torque reserve is sufficient to reach the enthalpy threshold which is required for the catalyst shutdown.

In another aspect of the present disclosure, the at least one exhaust parameter measuring device each defines a temperature sensor, a mass air flow sensor, and a mass fuel flow sensor.

In various aspects, a method for determining the catalytic radiation conditions of a catalyst during transient engine speed and transient engine load includes: measuring exhaust conditions entering the catalyst using an exhaust parameter measurement device; Forwarding an output from the exhaust parameter measuring device to a processor; Calculating an enthalpy of the catalyst in the processor; and repeatedly comparing the enthalpy of the catalyst with a predetermined enthalpy threshold required to achieve a catalyst shutdown stored in a memory.

In a further aspect of the present disclosure, the method includes: confirming that the catalyst is at or below a required catalyst shutdown temperature; and performing the computing step in a calculation block, the computing block receiving inputs including an exhaust temperature, a mass air flow, a mass fuel flow and a catalyst heating mode.

In another aspect of the present disclosure, the method includes: determining whether the calculated enthalpy of the catalyst is greater than the predetermined enthalpy threshold.

In another aspect of the present disclosure, the method includes: determining whether a catalyst warm-up mode is activated; and requesting a torque reserve to increase an exhaust gas temperature.

In another aspect of the present disclosure, the method includes: identifying a first variable that defines an energy threshold required to achieve catalyst shutdown and inputting the first variable into a compare block; Inputting a result from the calculation step into the comparison block as a second variable; and comparing the first variable with the second variable to determine if the second variable is greater than the first variable, and if the comparison is negative, the torque reserve is deemed sufficient to achieve an enthalpy threshold appropriate for the second variable Catalyst shutdown is required.

In various aspects, a method for determining catalytic shutdown conditions of a catalyst during transient engine speed and transient engine load includes: measuring exhaust conditions entering the catalyst using at least one exhaust parameter measurement device; Forwarding an output from the at least one exhaust parameter measuring device to a processor; continuously calculating an enthalpy of the catalyst in the processor; repeatedly comparing the calculated enthalpy of the catalyst with a predetermined enthalpy threshold required to achieve catalytic radiation stored in a memory; and calculating a cumulative mass flow past the catalyst.

In another aspect of the present disclosure, the method includes: calculating a cumulative mass flow past the catalyst; and determining if: a) the enthalpy of the catalyst is greater than the predetermined enthalpy threshold, and b) the cumulative mass flow is less than a predetermined cumulative mass flow threshold.

In another aspect of the present disclosure, the method includes: requesting a torque reserve to increase an exhaust gas temperature; and calculating and integrating the torque reserve.
Other applications will be apparent from the description provided herein. It is to be understood that the description and specific examples are for the purpose of illustration only and are not intended to be construed as including Scope of the present disclosure.

list of figures

• 1 ist eine schematische Darstellung eines Fahrzeugantriebsstrangs und eines Bordnetzes zum Durchführen einer Kaltstart-Emissionsreduzierungsstrategie gemäß einem Aspekt der vorliegenden Offenbarung;
• 2 ist ein Flussdiagramm für den Katalysatoraufwärmmodus unter Verwendung der Abgasenthalpie und des kumulativen Abgasmassenstromschwellenwerts als Katalysatorabschaltdiagnose;
• 3 ist ein Flussdiagramm für den Katalysatoraufwärmmodus unter Verwendung einer Drehmomentreserve als Katalysator-Abschaltaustrittsstrategie; und
• 4 ist ein Flussdiagramm für den Katalysatoraufwärmmodus unter Verwendung der Abgasenthalpie als Katalysator-Abschaltaustrittsstrategie.

The drawings described herein are for illustration only and are not intended to limit the scope of the present disclosure in any way.

• 1 FIG. 10 is a schematic illustration of a vehicle powertrain and on-board network for performing a cold start emission reduction strategy in accordance with an aspect of the present disclosure; FIG.
• 2 FIG. 12 is a flowchart for the catalyst warm-up mode using the exhaust enthalpy and the cumulative exhaust gas mass flow threshold as a catalyst cut-off diagnosis; FIG.
• 3 FIG. 12 is a flowchart for the catalyst warm-up mode using a torque reserve as a catalyst shut-down exit strategy; FIG. and
• 4 FIG. 12 is a flowchart for the catalyst warm-up mode using exhaust enthalpy as a catalyst shutoff exit strategy.

DETAILED DESCRIPTION

The following description of one aspect is merely exemplary in nature and is not intended to limit the present invention in its applications or uses. For the sake of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, activation refers to the operation of all cylinders of the engine. Disabled refers to operation with less than all cylinders of the engine (one or more cylinders are not active). The term "processor" as used herein refers to an application specific integrated circuit (ASIC), an electronic circuit, a shared, dedicated or group processor module and a memory that together comprise one or more software or firmware programs, a combinational logic circuit or performs other suitable components that provide the described functionality.

Referring now to 1 can a vehicle 10 Any type of motor vehicle including combustion engine vehicles and hybrid vehicles and includes an engine 12 that a gear 14 drives. The gear 14 is either an automatic or a manual transmission that is powered by the engine 12 via a corresponding torque converter or a clutch 16 driven. Air flows through a throttle 18 in the engine 12 , The motor 12 includes N-cylinder 20 , One or more of the cylinders 20 can be selectively disabled during engine operation. Even though 1 shows eight cylinders (N = 8), it should be noted that the engine 12 additional or less cylinders 20 may include. For example, engines with 4, 5, 6, 8, 10, 12 and 16 cylinders are being considered. Air flows over an intake manifold 22 in the engine 12 and gets in the cylinders 20 burned with fuel.

According to several aspects, when the vehicle 10 a hybrid vehicle includes the vehicle 10 also an electric machine 24 and a battery 26 , The electric machine 24 is operable in each case in a motor and a generator mode. In motor mode, the electric machine 24 through the battery 26 powered and drives the gearbox 14 at. In generator mode, the electric machine 24 through the transmission 14 powered and generates electrical energy required to charge the battery 26 is used. It should also be apparent that the battery 26 next to the electric machine 24 can supply other vehicle accessories.

A controller 28 communicates with the engine 12 , the electric machine 24 and receives various inputs from exhaust parameter measuring devices, such as sensors, as described herein. A driver presses an accelerator pedal 30 to the throttle 18 to regulate. In particular, a pedal position sensor generates 32 a pedal position signal sent to the controller 28 is transmitted. The control 28 generates a throttle control signal based on the pedal position signal. A throttle actuator (not shown) provides the throttle 18 based on the throttle control signal to the air flow in the engine 12 to regulate.

The driver also operates a brake pedal 34 to regulate the vehicle braking. When pressing the brake pedal 34 generates a brake position sensor 36 a brake pedal position signal sent to the controller 28 is transmitted. The control 28 generates a brake pedal position signal based on the brake control signal. A brake system (not shown) adjusts vehicle braking based on the brake control signal to control vehicle speed. Next to the pedal position sensor 32 and the brake position sensor 36 generates an engine speed sensor 38 based on the engine speed, a signal. An intake manifold absolute pressure (MAP) sensor 40 generated based on a pressure of the intake manifold 22 a signal. A throttle position sensor (TPS) 42 generates a signal based on a throttle position. A mass air flow sensor (MAF) 44 generated based on the airflow into the throttle 18 a signal.

When vehicle load requirements can be met with torque less than all cylinders 20 is generated, the controller switches 28 the engine 12 in deactivated mode. In an exemplary embodiment, the N / 2 cylinders are 20 ' disabled, with one or more cylinders 20 ' can be disabled. After disabling the selected cylinder 20 ' increases the control 28 the performance of the remaining cylinders 20 ' by taking the position of the throttle 18 established. The engine load is determined based on MAP, MAF, RPM and other inputs. For example, if an engine vacuum is above a threshold at a certain speed, the engine load may be less than all cylinders and the engine 12 is operated in deactivated mode. If the vacuum is below a second threshold for the given speed, the engine load can not be provided by less than all the cylinders and the engine 12 is operated in activated mode.

The control 28 provides engine speed control to adjust the engine output torque through intake air / fuel and spark timing controls to maintain a desired engine speed. The control 28 provides an electronic ignition timing (EST) signal, which is sent over one wire 46 to an ignition control 48 is issued. The ignition control 48 responds to the EST signal to timed output of the drive signals to the spark plugs 50 for burning the fuel charge in the engine cylinders 20 provide. The EST signal may also provide spark timing signals over a wide time range. In general, it is desirable that the ignition timing be before the top dead center of the piston, and as the engine speed increases, it is typical to further advance the ignition timing.

It is also known in the art to delay the ignition timing to the center after top dead center. The ignition timing may be retarded, for example, to quickly limit engine output torque or during cold starts of the engine to raise the exhaust gas temperature, substantially the commercial engine output torque for heat. The exhaust gas flow from the engine 12 is about at least one catalyst 52 with a catalyst 54 delivered, which is required to reach a given temperature (definition of "catalyst shutdown") before its oxidation and reduction reactions are optimally performed. The spark retard may be retarded during cold starts of the engine to increase the exhaust gas temperature faster, and thus the temperature of the catalyst 54 increase as quickly as possible and thereby reach the fuel emission standards more quickly. The predetermined temperature that defines the catalyst shutdown and the conditions that define a total enthalpy value that also define the catalyst shutdown may be stored in memory 59 the controller 28 get saved.

As another method for raising the temperature of the catalyst 54 during the cold start of the engine, an "increased idle" can be performed, wherein the control 28 for a temporarily increased engine idle speed beyond the engine's normal idle speed. The increased idle may extend for a period of about 10 to 40 seconds after the engine starts. A setpoint is used to control engine speed and spark timing or to decelerate at increased idle.

During certain periods of operation, the entire period for increased idle may not be available. For example, if the vehicle is powered by the battery 26 powered electric machine 24 accelerates to the gearbox 14 but the torque is insufficient to cover the torque demand, an engine start and a torque output may be required before the catalyst 54 can reach the minimum required temperature for the catalyst shutdown. Under these conditions, it is desirable to continue to meet emissions standards while engine speed meets torque demand. To determine how such increased-idle events affect catalyst deactivation, one or more exhaust temperature sensors may be used 56 used either upstream or downstream, or both upstream and downstream of the catalyst 52 can be arranged. A mass fuel flow sensor 58 can also be provided.

With reference to 2 and again 1 In several aspects, the exhaust enthalpy under conditions such as transient engine speed and transient engine load is used as input to a diagnostic method that defines a parameter for controlling the engine's cold start emission reduction mode. The determination of exhaust enthalpy to identify when catalyst deactivation occurs provides an alternative approach to determining exhaust gas measurement deviations during a prescribed stationary engine operating condition, such as during increased idle when the steady state operating condition may not be available. The exhaust gas enthalpy may be determined by the inlet or outlet temperature of the catalyst, for example the exhaust gas temperature sensor 56 , With further reference to 1 There are one or more temperature sensors, the example only a single exhaust gas temperature sensor 56 in front of the catalyst (s) 52 , which are used to identify exhaust gas temperatures. Additional temperature sensors (not shown) may be downstream of each catalyst 52 be arranged.

The exhaust gas enthalpy can also be summed up by adding energy to the catalysts 52 be determined. In this approach, the total energy input for the catalysts 52 certain exhaust enthalpy using the output of sensors, such as the temperature sensor 56 , the air mass flow sensor (MAF) 44 and with reference to 1 described fuel mass flow sensor 58 calculated.

According to several aspects are in an enthalpy summation algorithm 60 an exhaust gas temperature 62 , a mass airflow 64 , a mass fuel flow 66 and a catalyst warm-up mode 68 inputs to a calculation block 70 , In the calculation block 70 First, it is identified if the state of the catalyst warm-up mode is True 72 which means that the catalyst is at a temperature below the temperature required for catalyst shutdown, such as the catalyst 52 at an ambient temperature. When the state of the catalyst warm-up mode is True 72 is, becomes an exhaust enthalpy 74 calculated, and it also becomes a cumulative mass flow 76 on the catalyst 52 for the exhaust enthalpy 74 calculated over. These values can each be included in the determination of whether the energy and temperature conditions for catalyst shutdown have been achieved.

$${\text{m }}_{\text{Im Strom}}=-\left({\mathrm{\psi }}_{\text{Luft}}+{\dot{\text{m}}}_{\text{Kraftstoff}}\right)\text{ dt}$$

The in the calculation block 70 certain exhaust enthalpy 74 can with the following integral equations ( 1 ) and ( 2 ) be calculated: $${\text{Q}}_{\text{In the stream}}={\displaystyle \int {\dot{\text{m}}\sout{\text{x}}\text{C}}_{\text{p}}\left(\text{T}\right){\sout{\text{x}}\text{T}}_{\text{in}}\text{dt}}$$

$${\text{m}}_{\text{In the stream}}=-\left({\mathrm{\psi }}_{\text{air}}+{\dot{\text{m}}}_{\text{fuel}}\right)\text{dt}$$

Where Q _{in the stream is} the cumulative flow of energy into the catalyst 52 is, and m _{In the stream is} the cumulative mass flow that is at the catalyst 52 passes.

As a diagnostic tool is in a subsequent comparison block 78 determines whether a) the calculated exhaust enthalpy 74 is greater than a predetermined enthalpy threshold, AND b) is the cumulative mass flow 76 is less than a given cumulative mass flow threshold. If an exit 82 from the comparison block 78 is positive for the above items (a) and (b) becomes a diagnostic passing signal 84 generated. If an exit 86 from the comparison block 78 is negative, is in a cumulative block 88 determines if the cumulative mass flow 76 is less than a predetermined mass flow threshold. If an exit 92 from the cumulative block 88 is negative, becomes a diagnostic error signal 94 generated.

If an exit 96 from the cumulative block 88 is positive, is in a determination block 98 determines if the condition 68 the catalyst warm-up mode is false 100 and whether the cumulative mass flow 76 greater than a predetermined minimum threshold 102 is. If an exit 104 of the determination block 98 is negative, the program returns to the calculation block 70 back. If an exit 106 from the determination block 98 is positive, the diagnostic test is considered indefinite and it becomes an indeterminate signal 108 of the diagnostic test. The enthalpy in the catalyst 52 is measured until a predetermined energy level is reached, assuming that the catalyst radiation is reached. The diagnosis compares both energy and mass flow. If the energy flow is greater than the mass flow, then catalyst radiation may occur and the diagnostic run is identified. If the mass flow is greater than the energy flow, the diagnosis fails and is repeated. The diagnosis is not time-dependent and will continue unless an error-pending state is identified that defines the indeterminate result. The indefinite result may occur, for example, when an engine start, but the engine is switched off before the expiration of a time sufficient to achieve the catalyst radiation.

With reference to 3 and again on the 1 and 2 For example, a method of determining exhaust enthalpy integrates a torque reserve as a parameter for an exit strategy from the catalyst warm-up mode. The torque reserve is defined as a torque potential value of the crankshaft. A torque reserve may be available due to a retarded spark timing during a cold start mode of the engine that delays combustion and thus produces a difference between the potential value of the torque and a torque actually delivered. The torque reserve values are integrated over time, and when a threshold based on a cumulated exhaust flow value is reached, the torque reserve value is used as the basis to determine if the torque reserve value is being used required increased exhaust gas enthalpy was achieved in order to achieve a catalytic radiation.

According to an integration algorithm 110 to the enthalpy of the torque reserve is at a determination block 114 a catalyst warm-up mode status 112 certainly. If an exit 116 from the determination block 114 is positive, indicating that the catalyst warm-up mode is activated, becomes in a request step 118 made a request for a torque reserve to increase an exhaust gas temperature. After requesting the torque reserve 118 is in a calculation block 120 calculated and integrated a torque reserve. The result from the calculation block 120 is the first variable in a comparison block 122 entered. A second variable, which defines an energy threshold required to achieve catalyst shutdown, becomes a second calculation block 124 get and in the comparison block 122 entered. As mentioned above, the energy threshold required to achieve a catalyst cutoff used as a second variable is integrated as an accumulated exhaust gas flow value. In the comparison block 122 For example, the second variable defining the energy threshold required to achieve a catalyst shutdown is compared to the first variable obtained from the calculation block 120 is obtained to determine if the second variable is greater than the first variable. If an exit 126 from the comparison block 122 is negative, the available torque reserve is sufficient to achieve the energy threshold required for catalyst deactivation and the algorithm returns to the request step 118 back and repeat this.

If an exit 128 from the comparison block 122 is positive, the available torque reserve is insufficient to achieve the energy threshold required for catalyst shutdown. The algorithm provides a response gate 130 available, which is the output 128 from the comparison block 122 receives. If, in addition, an output of the determination block 114 is negative, indicating that the catalyst warm-up mode is not activated, becomes the negative response of the determination block 114 also to the response gate 130 forwarded. Every reaction coming from the negative response gate 130 is received leads to a mark 132 indicating that no torque reserve should be requested, and the algorithm ends in one step 134 ,

With reference to 4 and again on the 1 to 3 For example, a method of determining exhaust enthalpy integrates cumulative exhaust enthalpy as a parameter for an exit strategy from the catalyst warm-up mode. The torque reserve, as defined above, is used to increase the exhaust gas temperature. The exhaust gas enthalpy values into the catalyst are integrated over time, and upon reaching a threshold, the thermal energy threshold for catalyst deactivation is used as the basis to determine if the required increased exhaust enthalpy has been achieved to achieve catalytic shutdown.

According to an integration algorithm 136 to the enthalpy of the catalyst is at a determination block 140 a catalyst warm-up mode status 138 certainly. If an exit 142 from the determination block 140 is positive, indicating that the catalyst warm-up mode is activated becomes a request step 144 made a request for a torque reserve to increase an exhaust gas temperature. After requesting the torque reserve 144 is in a calculation block 146 an exhaust gas enthalpy into the catalyst 54 calculated and integrated. The result from the calculation block 146 is the first variable in a comparison block 148 entered. A second variable, which defines an energy threshold required to achieve catalyst shutdown, becomes a second calculation block 150 get and in the comparison block 148 entered. As mentioned above, the energy threshold required to achieve a catalyst cutoff used as a second variable is integrated as an accumulated exhaust gas flow value. In the comparison block 148 For example, the second variable defining the energy threshold required to achieve a catalyst shutdown is compared to the first variable obtained from the calculation block 146 is obtained to determine if the second variable is greater than the first variable. If an exit 152 from the comparison block 148 is negative, the available exhaust enthalpy is sufficient to reach the energy threshold required for the catalyst shutdown, and the algorithm returns to the request step 144 back and repeat this.

If an exit 154 from the comparison block 148 is positive, the available exhaust enthalpy is insufficient to achieve the energy threshold required for the catalyst radiation. The algorithm provides a response gate 156 available, which is the output 154 from the comparison block 148 receives. If, in addition, an output of the determination block 140 is negative, indicating that the catalyst warm-up mode is not activated, becomes the negative response of the determination block 140 also to the response gate 156 forwarded. Every reaction coming from the negative response gate 156 is received leads to a mark 158 indicating that no torque reserve should be requested, and the algorithm ends in one step 160 ,

A system and method for determining exhaust enthalpy under conditions including transient engine speed and transient engine load of the present disclosure offers several advantages. These include the use of exhaust enthalpy as input to a diagnostic procedure as opposed to using measurement deviations from a prescribed constant engine operating condition. The present method also provides a general strategy for warming up the transducer and the ability to diagnose a cold start strategy for load operation. The present method is energy-based and can be used both in stationary and in the stationary speed and load range. The strategy uses the exhaust enthalpy, which introduces all of the heat energy into the catalytic converter and is considered a maintenance parameter that can be used under all driving conditions. In various aspects, the present method provides for two exit strategies, including a first strategy regarding an amount of torque reserve required to increase exhaust temperature to achieve catalyst radiation, and a second strategy for total exhaust enthalpy into the catalyst to achieve catalyst shutdown.

The description of the present disclosure is to be considered as an example only, and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variants are not to be regarded as a departure from the spirit and scope of the invention.

Claims (9)

A system for determining catalytic cut-off conditions during transient engine speed and transient engine load, comprising: a catalyst configured to receive the exhaust gas output of an engine; at least one exhaust parameter measuring device configured to measure at least one parameter of the exhaust gas entering the catalyst; a processor configured to: Receiving the output from the at least one exhaust parameter measuring device; continuously calculating an enthalpy of the catalyst; and repeatedly comparing the enthalpy of the catalyst with a predetermined enthalpy threshold required to achieve a catalyst shutdown stored in a reservoir. System after Claim 1 10, further comprising a calculation block configured to receive inputs including an exhaust inlet temperature, a mass air flow, a mass fuel flow, and a catalyst warm-up mode state for calculating the enthalpy of the catalyst. System after Claim 2 wherein in the calculation block, the catalyst warm-up mode condition that is true, before calculating the enthalpy of the catalyst is initiated, identifies the catalyst warm-up mode condition as true, wherein the catalyst is at a temperature below that required for the catalyst shutdown. System after Claim 2 wherein the processor is configured to calculate a cumulative mass flow through the catalyst, the system further including a comparison block configured to: a) determine whether the calculated enthalpy of the catalyst is greater than the predetermined enthalpy threshold; and b) if the cumulative mass flow is less than a predetermined cumulative mass flow threshold. System after Claim 4 wherein the system is configured to generate a diagnostic pass signal when an output from the compare block for (a) and (b) is positive. System after Claim 4 in which, when an output from the comparison block for (a) and (b) is negative, a diagnostic error signal is generated. System after Claim 2 wherein the processor is configured to calculate a cumulative mass flow past the catalyst, the system further including a determination block, wherein if it is determined that the condition of the catalyst warm-up mode is false and if the cumulative mass flow is greater than a predetermined minimum threshold. System after Claim 7 wherein the system is configured to generate an indeterminate diagnostic test signal when an output of the determination block is positive. System after Claim 1 , further comprising: a determination block configured to determine an activated state of the catalyst warm-up mode, and when an output of the determination block indicating the catalyst warm-up mode that is activated is positive, a request for a torque reserve for increasing an exhaust gas temperature is output; and a first calculation block configured to adjust the torque reserve after Calculate and integrate requirement for the torque reserve.

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